Ultrasonic Pachymetry
The laser corrects the refractive errors (myopia, hyperopia or astigmatism), modifying the anterior contour of the cornea, having to remove some of the corneal tissue. Nowadays, it is well defined what the minimum thickness of the cornea should be after surgery.
For this reason, the measurement of central corneal thickness, preoperative and postoperative, is a fundamental exam in refractive surgery.
Pachymetry is also an important exam in the determination of Intraocular Pressure (IOP), since the thickness of the cornea influences its reading, which is already considered in the latest generation of air puff tonometers, which display the corrected IOP value.